Non-volatile memory devices with charge storage insulators and methods of fabricating such devices

ABSTRACT

A non-volatile memory device comprises a cell region defined at a substrate and a plurality of device isolation layers formed in the cell region to define a plurality of active regions. A charge storage insulator covers substantially the entire top surface of the cell region. A plurality of gate lines are formed on the charge storage insulator that cross over the device isolation layers. Conductive patterns are disposed between predetermined gate lines that penetrate the charge storage insulator to electrically connect with the active regions. According to the method of fabricating the device, a plurality of device isolation layers are formed in the substrate and then a charge storage insulator is formed on an entire surface of the substrate and the device isolation layers. A plurality of parallel gate lines that cross over the device isolation layers are formed on the charge storage insulator and then conductive patterns are formed between predetermined gate lines. The conductive patterns penetrate the charge storage insulator and electrically connect with the active regions.

CLAIM OF PRIORITY

This application claims priority under 35 U.S.C. §120 as acontinuation-in-part of U.S. patent application Ser. No. 11/272,638,filed Nov. 14, 2005 now U.S. Pat. No. 7,495,284, which claims priorityas a continuation-in-part of U.S. patent application Ser. No.10/712,426, filed Nov. 13, 2003 now U.S. Pat. No. 6,995,424, whichclaims priority under 35 U.S.C. §119 from Korean Patent Application No.2003-01566 filed Jan. 10, 2003, in the Korean Intellectual PropertyOffice. Accordingly, this application claims priority to each of theabove-identified applications. The disclosures of each of the aboveapplications are incorporated herein in their entirety by reference.

FIELD OF THE INVENTION

The present invention relates to memory devices and more specifically tonon-volatile memory devices and methods for fabricating such devices.

BACKGROUND OF THE INVENTION

Non-volatile memory devices are memory devices that can store data whenthe power is cut off. Known types of non-volatile memory devices includeflash memory devices, ferroelectric memory devices, phase changeablememory devices and magnetic memory devices.

Flash memory non-volatile memory devices include unit memory cells thathave a structure similar to the structure of a MOS transistor. Thesedevices do not require a separate data storage element and, as such, thecell region may be highly integrated. Generally speaking, a flash memorydevice may have one of two representative structures. The first suchstructure stores charge in a conductive floating gate, while the secondrepresentative structure stores the charge in a charge storageinsulator. The flash memory devices that have the stricture in which thecharge is stored in a charge storage insulator may provide certainadvantages, such as low program and erase voltages and excellentendurance and retention. In addition, multi-bit programmable versions ofthese devices can be fabricated.

FIGS. 1 through 5 depict a conventional flash memory non-volatile memorydevice that uses a charge storage insulator. As shown in the top planeview of the device provided in FIG. 1, the device includes a pluralityof device isolation layers 28 a that are formed on predetermined regionsof a substrate 10 (the substrate is not shown in FIG. 1). An activeregion is defined between these device isolation layers 28 a. A gateelectrode 30 is disposed over the active region and the device isolationlayers 28 a. A charge trapping layer 16 is interposed between the gateelectrode 30 and the active region.

FIGS. 2 through 5 are cross-sectional views taken along the line A-A ofFIG. 1 illustrating various steps during the fabrication of theconventional non-volatile memory device depicted in FIG. 1. Theconventional non-volatile memory device can be fabricated by forming alower insulation layer 14, a charge trapping layer 16 and an upperinsulation layer 18 on a substrate 10. A first conductive layer 20 and ahard mask layer 22 are formed on the upper insulation layer 18. The hardmask layer 22 and the first conductive layer 20 are patterned. Then, theupper insulation layer 18, the charge trapping layer 16, the lowerinsulation layer 14 and the substrate 10 are patterned to form thetrench regions 12 that are depicted in FIG. 2.

A thermal process is then applied to the substrate 10 with the trenchregions 12 to form a trench oxide layer 24 on the inner sides of thetrench regions 12 (see FIG. 3). Then, an insulation layer 28 is formedon the trench oxide layer 24 to fill the trench regions 12. Generally,the substrate 10 and the first conductive layer 20 are formed ofsilicon. As a result, both the portion of the substrate 10 that contactsthe lower insulation layer 14 mid the portion of the first conductivelayer 20 that contacts the upper insulation layer 18 may be partiallyetched (see reference numeral 26 on FIG. 3). Moreover, when silicon isthermally oxidized it expands such that it approximately doubles involume. The tensile stress and compressive stress that results from theoxidation of the silicon substrate 10 and the first conductive siliconlayer 20 may act to deteriorate the charge trapping layer 16. Inaddition, etch damage may occur during the formation of the trenchregions 12 that leaves defects at one or both edges of the chargetrapping layer 16 where the charge trapping layer 16 is aligned to thesidewalls of the trench regions 12.

As shown in FIG. 4, a chemical-mechanical polishing process may then beapplied to the insulation layer 28. The insulation layer 28 is firstpolished until the hard mask layer 22 is exposed and the insulationlayer 28 is divided into device isolation layers 28 a that fill thetrench regions 12. Then, the hard mask layer 22 is removed to expose thefirst conductive layer 20.

As shown in FIG. 5, a polysilicon layer 30 and a silicide layer 32 arethen formed over the entire surface of the substrate. The polysiliconlayer 30, the silicide layer 32 and the first conductive layer 20 arepatterned to form a gate electrode 34 that crosses over the deviceisolation layers 28 a. As discussed above, the conventional non-volatilememory device illustrated in FIG. 5 can have defects at the regionsneighboring the device isolation layers 28 a. These defects candeteriorate the data storage and endurance characteristics of thedevice.

SUMMARY OF THE INVENTION

Pursuant to embodiments of the present invention, non-volatile memorydevices are provided that comprise a substrate on which a plurality ofdevice isolation layers are formed that define a plurality of activeregions. These devices further include a charge storage insulator thatis formed on the plurality of active regions and the plurality of deviceisolation layers, as well as a plurality of word lines formed on thecharge storage insulator crossing over the active regions. A pluralityof conductive patterns may be disposed between the word lines thatpenetrate the charge storage insulator to electrically connect with theactive region.

The charge storage insulator may comprise a lower oxide layer, a chargetrapping layer and an upper oxide layer. The upper oxide layer may be aninsulative metal oxide layer. The plurality of device isolation layersand the plurality of active regions may be located in a cell region ofthe device, and the charge storage insulator may be formed onsubstantially the entire surface of the cell region.

In additional embodiments of the present invention, the plurality ofdevice isolation layers formed in the substrate may also define aplurality of second active regions in a high voltage region of thedevice and a plurality of third active regions in a low voltage regionof the device. A high voltage gate pattern crosses over the secondactive region and a low voltage gate pattern crosses over the thirdactive region. An insulation layer may also be interposed between thehigh voltage gate electrode and the second active region, and aninsulation layer may be interposed between the low voltage gateelectrode and the third active region. These insulation layers maycomprise single layer, double layer and/or triple layer insulationlayers. The top surface of the device isolation layers may be disposedhigher than the top surface of the active regions.

The high voltage gate electrode and the low voltage gate electrode maycomprise a lower gate pattern that is formed between a pair of deviceisolation layers and an upper gate pattern. The upper gate pattern maybe formed on the lower gate pattern and may overlap a portion of thedevice isolation layers.

Methods of fabricating non-volatile memory devices are also disclosed.In embodiments of these methods, the device is fabricated by forming aplurality of device isolation layers in the cell region of a substrateto define a plurality of active regions, and then forming a chargestorage insulator on the active regions and the device isolation layers.A plurality of gate lines may then be formed on the charge storageinsulator, and conductive patterns may also be formed that penetrate thecharge storage insulator between some of the plurality of gate lines toelectrically connect with the active region. Trenches in which thedevice isolation layers are formed may be fabricated by forming a padinsulation layer and a hard mask layer on the substrate and thenpatterning the hard mask layer, the pad insulation layer and thesubstrate to form the trenches. Then an insulation layer may be formedover substantially the entire surface of the cell region, and thisinsulation layer may be polished down to the hard mask layer viapolishing so as to divide the insulation layer into a plurality ofdevice isolation layers.

According to further embodiments of the present invention, non-volatilememory devices are provided that include a substrate having a pluralityof device isolation layers and a plurality of active regions between thedevice isolation layers. A charge storage insulation layer is on theplurality of active regions and the plurality of device isolationlayers. The charge storage insulation layer includes a lower insulationlayer, a charge storage layer on the lower insulation layer, and anupper insulation layer on the charge storage layer. A plurality ofspaced apart gate lines are on the charge storage insulation layer, andthese gate lines define a plurality of regions between the gate lines.In these devices, the lower insulation layer and the charge storagelayer cover the plurality of active regions and the plurality of deviceisolation layers in the plurality of regions between the gate lines. Incertain embodiments of the present invention, the charge storage layermay be an insulation layer, a silicon-rich oxide, or an insulation layerthat includes conductive dots. The conductive dots, if included, maycomprise a semiconductor or a metal. The upper insulation layer may alsocover the plurality of active regions and the plurality of deviceisolation layers in the plurality of regions between the gate lines. Insome embodiments, the thickness of the upper insulation layer in theregions between the gate lines may be smaller than the thickness of theupper insulation layer in the regions below the gate lines.

The upper insulation layer may comprise at least one metal oxide layersuch as, for example, an oxide of metal listed in Group III or VB of thePeriodic Table. The metal in the metal oxide layer may be doped, forexample, with at least one element listed in Group IV of the PeriodicTable. In specific embodiments, the metal oxide layer may compriseAl₂O₃, HfO₂, HfAlO, HfAlON, ZrO₂, ZrAlO, HfSiO, and/or HfSiON. Inaddition, a protective insulation layer may be provided between the atleast one metal oxide layer and the gate lines.

Pursuant to still further embodiments of the present invention,non-volatile memory devices are provided that comprise a substrateincluding a plurality of device isolation layers and a plurality ofactive regions between the device isolation layers. A charge storageinsulation layer is provided that covers the plurality of deviceisolation layers and the plurality of active regions. A plurality ofspaced apart gate lines that define a plurality of regions between thegate lines are provided, wherein a first subset of the regions betweenthe gate lines have a first width and a second subset of the regionsbetween the gate lines have a second width that is greater than thefirst width. The devices may also include spacer insulation layers onsidewalls of the gate lines that extend into respective regions betweenthe gate lines, as well as a plurality of interconnection patterns thatare provided in respective ones of the second subset of the regionsbetween the gate lines that electrically connect to the substrate. Inthese devices, each spacer insulation layer that extends into the firstsubset of the regions between the gate lines connects with another ofthe spacer insulation layers, while the spacer insulation layers thatextend into the second subset of the regions between the gate lines arespaced apart from each other.

Pursuant to additional embodiments of the present invention,non-volatile memory devices are provided that comprise a substratehaving a plurality of device isolation layers that define a plurality ofactive regions. In these devices, a charge storage insulation layer isprovided on the plurality of device isolation layers and the pluralityof active regions. A plurality of spaced apart gate lines (wherein eachgate line is a word line, a ground select line or a string select line)are on the charge storage insulator. Sidewall spacers are provided onsidewalls of the gate lines. Each sidewall spacer that is on a word lineconnects with the sidewall spacer on an adjacent gate line.

Pursuant to other embodiments of the present invention, methods offabricating non-volatile memory devices are provided in which aplurality of device isolation layers are formed in the substrate todefine a plurality of first active regions in a cell region of thedevice, and a plurality of second active regions in a peripheral regionof the device. A charge storage insulation layer is formed on at leastthe first active regions. A plurality of gate lines are formed on thecharge storage insulation layer. A plurality of gate electrodes areformed over the second active regions. A first ion implantation processis carried out in the cell region. A second ion implantation process iscarried out in the cell region and the peripheral region. Source/drainregions are formed in the cell region and the peripheral region bycarrying out the first and the second ion implantation process.

In these embodiments, the methods may further comprise forming an ionimplantation mask on the substrate that exposes at least portions of thecell region and covers the peripheral region before carrying out thefirst ion implantation process, and removing the ion implantation maskafter carrying out the first ion implantation process and beforecarrying out the second ion implantation process. In these embodiments,the first ion implantation process may comprise a tilt ion implantationprocess. The first ion implantation process may further comprise anon-tilt ion implantation process. The non-tilt ion implantation processmay be carried out prior to the tilt ion implantation process. Where aninterval between the gate lines is L1, and a height of the gate linesfrom the charge storage insulation layer is L2, impurity ions may beinjected at an incident angle θ defined by θ≦tan⁻¹(L1/L2).

Pursuant to still further embodiments of the present invention, methodsof fabricating non-volatile memory devices are provided in which aplurality of active regions are defined in a substrate. A plurality ofgate lines are formed crossing over the active regions. A first ionimplantation process is carried out to form source/drain regions in theactive regions. The first ion implantation process comprises a tilt ionimplantation process.

In these embodiments, the methods may further comprise forming a chargestorage insulation layer on at least the active regions. The first ionimplantation process may further comprise a non-tilt ion implantationprocess. The non-tilt ion implantation may be carried out prior to thetilt ion implantation. The impurity ions may be injected at an incidentangle θ defined by θ≦tan⁻¹(L1/L2), where L1 is the interval betweenadjacent gate lines and L2 is a height of the gate lines from thesubstrate.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a top plane view of a non-volatile memory device that includesa conventional charge storage insulator.

FIGS. 2 through 5 are process cross-sectional views taken along a lingA-A of FIG. 1 that illustrate a method of manufacturing a conventionalnon-volatile memory device depicted in FIG. 1.

FIG. 6 is top plane view showing a cell region of non-volatile memorydevices in accordance with embodiments of the present invention.

FIG. 7A is a cross-sectional view, taken along the line B-B, of certainof the embodiments of the non-volatile memory devices depicted in FIG.6.

FIG. 7B is a cross-sectional view, taken along the line B-B, showingother embodiments of the non-volatile memory devices depicted in FIG. 6.

FIG. 8 is a cross-sectional view, taken along the line C-C, of thenon-volatile memory device depicted in FIG. 6.

FIG. 9 is a top plane view of the high voltage region of a nonvolatilememory devices in accordance with embodiments of the present invention.

FIG. 10 is a cross-sectional view taken along the line E-E of a highvoltage region of the non-volatile memory devices depicted in FIG. 9.

FIG. 11 is a top plane view of a low voltage region of nonvolatilememory devices in accordance with embodiments of the present invention.

FIG. 12 is a cross-sectional view taken along the line F-F of the lowvoltage region of the non-volatile memory devices depicted in FIG. 11.

FIGS. 13 through 20 are cross-sectional views illustrating steps offabricating non-volatile memory devices according to embodiments of thepresent invention.

FIGS. 21 through 26 are cross-sectional views illustrating steps offabricating non-volatile memory devices according to additionalembodiments of the present invention.

FIGS. 27 through 32 are cross-sectional views illustrating steps offabricating non-volatile memory devices according to further embodimentsof the present invention.

FIGS. 33 through 36 are cross-sectional views illustrating steps offabricating non-volatile memory devices according to other embodimentsof the present invention.

FIGS. 37 through 41 are cross-sectional views illustrating steps offabricating non-volatile memory devices according to still furtherembodiments of the present invention.

FIG. 42A is a cross-sectional view, taken along a line B-B of FIG. 6,illustrating a part of a wordline region WR of a non-volatile memorydevice according to embodiments of the present invention.

FIG. 42B illustrates a modified embodiment where spacer insulationlayers are formed on sidewalls of wordlines WN, ground select linesGSLn, and string select lines SSLn, respectively.

FIGS. 43A-47A and FIGS. 43B-47B are cross-sectional views of a wordlineregion, each being taken along a line B-B of FIG. 6, illustratingmodified versions of embodiments of the present invention, respectively.

FIGS. 48 through 50 are cross-sectional views illustrating methods offabricating non-volatile memory devices using ion implantation processesaccording to embodiments of the present invention.

DETAILED DESCRIPTION

Embodiments of the present invention will now be described more fullywith reference to the accompanying drawings, in which embodiments of theinvention are shown. This invention may, however, be embodied in manydifferent forms and should not be construed as limited to theembodiments set forth herein. Rather, these embodiments are provided sothat this disclosure will be thorough and complete, and will fullyconvey the scope of the invention to those skilled in the art. In thedrawings, the thickness of layers and regions are exaggerated forclarity. Like reference numerals refer to like elements throughout thisapplication.

It will be understood that, although the terms first, second, etc. maybe used herein to describe various elements, these elements should notbe limited by these terms. These terms are only used to distinguish oneelement from another. For example, a first element could be termed asecond element, and, similarly, a second element could be termed a firstelement, without departing from the scope of the present invention. Asused herein, the term “and/or” includes any and all combinations of oneor more of the associated listed items.

It will be understood that when an element such as a layer, region orsubstrate is referred to as being “on” or extending “onto” anotherelement, it can be directly on or extend directly onto the other elementor intervening elements may also be present. In contrast, when anelement is referred to as being “directly on” or extending “directlyonto” another element, there are no intervening elements present. Itwill also be understood that when an element is referred to as being“connected” or “coupled” to another element, it can be directlyconnected or coupled to the other element or intervening elements may bepresent. In contrast, when an element is referred to as being “directlyconnected” or “directly coupled” to another element, there are nointervening elements present. Other words used to describe therelationship between elements should be interpreted in a like fashion(i.e., “between” versus “directly between”, “adjacent” versus “directlyadjacent”, etc.).

Relative terms such as “below” or “above” or “upper” or “lower” or“horizontal” or “vertical” may be used herein to describe a relationshipof one element, layer or region to another element, layer or region asillustrated in the figures. It will be understood that these terms areintended to encompass different orientations of the device in additionto the orientation depicted in the figures.

It also will be understood that, as used herein, the terms “row” and“column” indicate two non-parallel directions that may be orthogonal toone another. However, the terms row and column do not indicate aparticular horizontal or vertical orientation.

Embodiments of the invention are described herein with reference tocross-section illustrations that are schematic illustrations ofidealized embodiments (and intermediate structures) of the invention.The thickness of layers and regions in the drawings may be exaggeratedfor clarity. Additionally, variations from the shapes of theillustrations as a result, for example, of manufacturing techniquesand/or tolerances, are to be expected. Thus, embodiments of theinvention should not be construed as limited to the particular shapes ofregions illustrated herein but are to include deviations in shapes thatresult, for example, from manufacturing. For example, an implantedregion illustrated as a rectangle will, typically, have rounded orcurved features and/or a gradient of implant concentration at its edgesrather than a binary change from implanted to non-implanted region.Likewise, a buried region formed by implantation may result in someimplantation in the region between the buried region and the surfacethrough which the implantation takes place. Thus, the regionsillustrated in the figures are schematic in nature and their shapes arenot intended to illustrate the actual shape of a region of a device andare not intended to limit the scope of the invention.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a”, “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises”“comprising,” “includes” and/or “including” when used herein, specifythe presence of stated features, integers, steps, operations, elements,and/or components, but do not preclude the presence or addition of oneor more other features, integers, steps, operations, elements,components, and/or groups thereof.

Unless otherwise defined, all terms (including technical and scientificterms) used herein have the same meaning as commonly understood by oneof ordinary skill in the art to which this invention belongs. It will befurther understood that terms used herein should be interpreted ashaving a meaning that is consistent with their meaning in the context ofthis disclosure and the relevant art and will not be interpreted in anidealized or overly formal sense unless expressly so defined herein.

FIG. 6 is a top plane view illustrating the cell region of non-volatilememory devices according to embodiments of the present invention. Asshown in FIG. 6, the cell region of the non-volatile memory device hasselection gate regions SR and a word line region WR. The selection gateregions SR are disposed on a substrate and the word line regions WR aredefined between the selection gate regions SR. Device isolation layersSTI are formed on the substrate, and a charge store layer 74 c coversthe entire surface of the cell region. As shown in FIG. 6, the chargestorage layer 74 c may be conformally formed both on the active regionsand on the device isolation layers STI that neighbor the active regions.

As is further illustrated in FIG. 6, a plurality of parallel gate linesGSL, SSL, w1˜wn may be disposed on the charge storage layer 74 c. Thegate lines cross over the device isolation layers STI. The gate linesmay comprise a plurality of word lines w1˜wn, ground selection lines GSLand string selection lines SSL. The plurality of word lines w1˜wn aredisposed in the word line region WR, and the ground selection lines GSLand string selection lines SSL are disposed in the selection gateregions SR. A selection gate region SR may be provided on both sides ofthe word line region WR. In a NAND type cell array, the two groundselection lines GSL are formed opposite to each other and a commonsource line CSL is disposed between the ground selection lines GSL. In aNAND type cell array the two string selection lines SSL are disposedopposite to each other and a plurality of bit line plugs BC are disposedbetween the string selection lines SSL. The common source line CSL isdisposed parallel to the word lines wn and is electrically connected tothe active regions that are provided between the device isolation layersSTI. The bit line plugs BC are also disposed parallel to the word lineswn and are also electrically connected to the active regions that areprovided between the device isolation layers STI. Thus, as illustratedin FIG. 6, the charge storage insulation layer 74 c may coversubstantially the entire surface of the cell region (although, as notedabove, the charge storage insulation layer 74 c may have openings thatexpose the device isolation layer STI and the active region in thevicinity of the common source line CSL and the bit line plugs BC).Alternately, the charge storage insulator 74 c may be formed only underthe gate lines so that it does not cover the entire surface of the cellregion.

FIG. 7A is a cross-sectional view, taken along a line B-B, of thenon-volatile memory device depicted in FIG. 6. FIG. 8 is across-sectional view, taken along the line D-D, of the non-volatilememory device depicted in FIG. 6. As shown best in FIG. 8, the cellregion of the non-volatile memory device may include a plurality ofparallel device isolation layers 56 that are formed in trenches providedin the substrate 50. The device isolation layers 56 define a pluralityof active regions 58. Turning to FIG. 7A it is seen that the cell regioncomprises a word line region WR where word lines w1˜wn are disposed andselection gate regions SR where selection gate lines SSLn and GSLn aredisposed. A charge storage insulator 74 c is formed on the substrateover the device isolation layers 56 and the active regions 58. Thecharge storage insulator 74 c comprises a lower oxide layer 64, a chargetrapping layer 66 and an upper oxide layer 68. The gate lines referencedabove may be formed on the charge storage insulator 74 c.

In a NAND type cell array, the gate insulation layer of the selectiontransistor may be thicker than that of the memory cell in order toreduce the possibility that the selection transistors are softlyprogrammed. Thus, the memory device of the present invention may furtherinclude an oxide layer 54 that is interposed between the substrate 50and the charge storage insulator 74 c.

FIG. 7B depicts an alternative embodiment of the non-volatile memorydevices of the present invention. As shown in FIG. 7B, in thisalternative structure the charge trap layer 66 and the upper oxide layer68 may be formed only in the word line region WR. In contrast to thedevice depicted in FIG. 7A, in the selection gate region the device ofFIG. 7B may omit both the charge trap layer 66 and the upper oxide layer68. As is also shown in FIG. 7B, an oxide layer 76 may be formed on thelower oxide layer 64.

As is best seen in FIG. 8, the top surface of the device isolationlayers 56 may be formed so that they are higher than the top surface ofthe active regions. According to additional aspects of the presentinvention, the sidewalls of the device isolation layers 56 adjacent theactive regions may have a predetermined angle of inclination orcurvature.

As best seen in FIGS. 7A and 7B, the gate lines may comprise groundselection lines GSL and string selection lines SSL and a plurality ofword lines w1˜wn. The gate lines cross over the device isolation layers56 and may be disposed so they are parallel to each other. The groundselection lines GSL and the string selection lines SSL are located inthe selection gate regions SR, and the word lines w1˜wn are located inthe word line region WR. Additionally, a conductive pattern is disposedbetween the ground selection lines GSL1 and GSL2 that is parallel to theword lines w1˜wn. This conductive pattern corresponds to a common sourceline CSL. A plurality of conductive patterns may also be disposedbetween the string selection lines SSL1 and SSL2, and these conductivepatterns may correspond to a bit line plug BC.

As shown best in FIGS. 7A and 7B, the common source line CSL is formedin an interlayer dielectric layer 130. As shown in FIG. 7A, the commonsource line CSL extends through charge storage insulator 74 c and theoxide layer 54 to electrically connect to the active regions 58.Alternatively, as shown in FIG. 7B, the common source line CSL extendsthrough lower oxide layer 64 and oxide layer 76 to electrically connectto the active regions 58. The common source line CSL may be formed asfollows. A first interlayer insulation layer 110 can be formed. Then,the first interlayer insulation layer 110, the charge storage insulator74 c and the oxide layer 54 can be patterned to form a groove.Alternatively, the interlayer insulation layer 110, the lower oxidelayer 64 and the oxide layer 76 can be patterned to form a groove. Thegroove can then be filled with a conductive layer to form the commonsource line CSL.

The bit line plugs BC are likewise formed in the interlayer dielectriclayer 130. As shown in FIG. 7A, the bit line plugs BC extend through thecharge storage insulator 74 c and the oxide layer 54 to electricallyconnect to the active regions 58. Alternatively, as shown in FIG. 7B,the bit line plugs BC extend through lower oxide layer 64 and oxidelayer 76 to electrically connect to the active regions 58. These bitline plugs BC can be formed in the following steps. When the firstinterlayer insulation layer 110 is formed as described above, the layer10 covers the area where the bit line plugs will be disposed. Then, asecond interlayer insulation layer 120 is formed on the first interlayerinsulation layer 110. The first and second interlayer insulation layers10 and 120 and the charge storage insulator 74 c may then be patternedto form a plurality of contact holes (see FIGS. 7A and 6).Alternatively, the first and second interlayer insulation layers 110 and120, the lower oxide layer 64 and the oxide layer 76 may then bepatterned to form a plurality of contact holes (see FIGS. 7B and 6). Thecontact holes expose the active region. These contact holes may then befilled with conductive material to form the bit line plugs BC. Note thatthe upper oxide layer 68 that is part of the charge store insulationlayer 74 c may be an insulation metal oxide such as, for example,aluminum oxide. Such an insulation metal oxide may be selectively etchedwith respect to silicon oxide so that the insulation metal oxide may beused as an etch stop layer during etching, of the first interlayerdielectric layer in order to form the groove (that is used to form thecommon source line CSL) or the contact holes (that are use to form thebit line plugs BC).

FIGS. 9 through 12 depict high and low voltage regions of non-volatilememory devices according to embodiments of the present invention. FIG. 9is a top plane view of a high voltage transistor (operating at highvoltage) that is disposed in the high voltage region of the device. FIG.10 is a cross-sectional view, taken along a line E-E of the device ofFIG. 9. As shown in FIGS. 9 and 10, in the high voltage region a pair ofdevice isolation layers 56 define an active region 60. A high voltagegate electrode 78 h is disposed on the active region 60. Additionally, ahigh voltage gate insulation layer 74 h may be interposed between thehigh voltage gate electrode 78 h and the active region 60 (see FIG. 10).This high voltage insulation layer 74 h may comprise one or more layers.

FIG. 11 is a top plane view of a low voltage transistor (that has a lowoperating voltage) that is disposed in the low voltage region of thedevice. FIG. 12 is a cross-sectional view, taken along a line F-F of thedevice of FIG. 11. As shown in FIGS. 11 and 12 a pair of deviceisolation layers 56 define an active region 62. A low voltage gateelectrode 78 l is disposed on the active region. Additionally, a lowvoltage gate insulation layer 74 l may be interposed between the lowvoltage gate electrode 78 l and the active region 62 (see FIG. 12). Thelow voltage gate insulation layer 74 l may include one or more layersand might be, for example, a double layer.

FIGS. 13 through 41 are cross-sectional views illustrating non-volatilememory devices according to embodiments of the present invention andmethods for fabricating these devices. In these figures, “b” refers tothe cell region of the device, “c” refers to the high voltage region ofthe device taken along the line E-E of FIG. 9 and “d” refers to the lowvoltage region of the device taken along the line F-F of FIG. 11. Theportion of these figures designated SR shows a cross-section of thedevice taken along the line C-C of FIG. 6. The portion designated WRshows a cross-section taken along the line D-D of FIG. 6.

FIGS. 13 through 20 are cross-sectional views showing non-volatilememory devices and methods of fabricating the same in accordance withfirst embodiments of the present invention. As shown in FIG. 13, a twolayer pad insulation layer 53 comprising a pad oxide layer 53 a and apad nitride layer 53 b is sequentially formed on a substrate 50 in thecell region “b”, the high voltage region “c” and the low voltage region“d” of the device. The pad insulation layer 53 of high voltage region“c” is removed. As shown in FIG. 14, a first oxide layer 52 a is formedon the substrate in the high voltage region “c” portion of the device.This may be accomplished by applying a thermal oxidation to thesubstrate 50.

As shown in FIG. 15, next the pad insulation layer 53 that was formed inthe low voltage region is removed. The pad insulation layer 53 that wasformed on the selection gate region SR of the cell region “b” is alsoremoved. This may be accomplished by selectively etching using aphotolithographic process. As is also shown in FIG. 15, a second oxidelayer 54 may be formed on the substrate in both the low voltage region“d” and the selection gate region SR of cell region “b” by applying athermal oxidation to the substrate 50. The first oxide layer 52 a thatwas formed in the high voltage region “c” may increase in thickness tobecome first oxide layer 52 due to the thermal oxidation process.

As shown in FIG. 16, a hard mask layer 55 may be formed over the entiresurface of the substrate 50 (i.e., it is deposited on the pad insulationlayer 53 in the word line region WR of cell region “b”, on the firstoxide layer 52 in the high voltage region “c” and on the second oxidelayer 54 in the low voltage region “d” and in the selection gate regionSR of cell region “b.”

As shown in FIG. 17, a plurality of device isolation layers 56 may thenbe formed on the substrate 50. The device isolation layers 56 definefirst active regions 58 in the cell region “b”, second active regions 60in the high voltage region “c”, and third active regions 62 in the lowvoltage region “d”. As shown in FIG. 17, the device isolation layers 56may have a trench structure. These device isolation layers 56 may beformed by successively patterning the hard mask layer 55, the padinsulation layer 53, the first oxide layer 52, the second oxide layer 54and the substrate 50 to form a plurality of trenches in the substrate50. An insulation layer is formed to fill in the trenches. Then,chemical mechanical polishing may be used to expose the hard mask layer55. This chemical mechanical polishing simultaneously turns theinsulation layer into a plurality of device isolation layers 56. Asshown in FIG. 17, the top surface of the device isolation layers 56 aredisposed higher than the top region of the active regions 58, 60, 62.

Thereafter, the hard mask layer 55 may be removed and a pad insulationlayer 53 may be formed on the cell region “b”. The hard mask layer 55and the pad nitride layer 53 b may be removed by a wet etch usingphosphoric acid. The pad oxide layer 53 a may be removed by a wet etchusing diluted solution of hydrogen fluoride (HF) or buffered oxideetchant (BOE). As a result, the protruding portions of the deviceisolation layers 56 in the of the cell region may have inclinedsidewalls and the edges of the protruded portions may have apredetermine curvature.

As shown in FIG. 18, a lower oxide layer 64, a charge trapping layer 66and an upper oxide layer 68 may be formed on entire surface of thesubstrate. The lower oxide layer 64 may be formed of, for example,silicon oxide, silicon oxynitride or metallic oxide. The charge trappinglayer 66 may be formed of silicon nitride or silicon oxynitride. Inparticular embodiments of the present invention, the charge trappinglayer 66 may be formed of a material having etch selectivity withrespect to the lower oxide layer. The upper oxide layer 68 may be formedof silicon oxide, silicon oxynitride or insulative metallic oxide suchas, for example, an aluminum oxide layer.

As shown in FIG. 19, the upper oxide layer 68 and the charge trappinglayer 66 are removed in the selection gate region SR of cell region “b”,the high voltage region “c” and the low voltage region “d”. A conductivelayer is then formed on the entire surface of the substrate 50. Theconductive layer may be formed by first forming a polysilicon layer 70and then forming a low resistance layer 72 on the substrate 50. The lowresistance layer 72 may be formed of tungsten, tungsten silicide,titanium silicide or cobalt silicide.

As shown in FIG. 20, the low resistance layer 72 and the polysiliconlayer 70 are successively patterned to form word lines 78 w in the wordline region WR of the cell region “b” and selection gate lines 78 s atthe selection gate region SR of cell region “b”. The word lines 78 w andthe selection gate lines 78 s cross over the device isolation layers 56.Additionally, a high voltage gate electrode 78 h is formed on the highvoltage region “c” and a low voltage gate electrode 78 l is formed onthe low voltage region “d”. The high voltage gate electrode 78 h crossesover the second active region 60 and the low voltage gate electrode 78 lcrosses over the third active region 62. A charge storage insulator 74 cthat comprises a stacked lower oxide layer 64, a charge trapping layer66 and an upper oxide layer 68 is interposed between the word lines 78 wand the first active regions 58. The charge storage insulator 74 c maybe formed on an entire surface of the word line region Wk oralternatively may be formed only under the word lines 78 w.

As is also shown in FIG. 20, a second oxide layer 54 and a lower oxidelayer 64 are interposed between the selection gate lines 78 s and thefirst active regions 58. A high voltage gate insulation layer 74 h isinterposed between the high voltage gate electrode 78 h and the secondactive region 60. As shown in FIG. 20, this high voltage gate insulationlayer 74 h may comprise a patterned first oxide layer 52 a onto which apatterned lower oxide layer 64 a is stacked. A low voltage gateinsulation layer 74 l is interposed between the low voltage gateelectrode 78 l and the third active region 62. This low voltage gateinsulation layer 74 l may comprise a patterned second oxide layer 52 aonto which a patterned lower oxide layer 64 a is stacked.

The charge trapping insulation layer 74 c may cover the entire surfaceof the word line region WR (not shown in the drawings). As noted above,the charge trapping insulation layer 74 c may comprise a stackedsemiconductor structure comprising a lower oxide layer 64, a chargetrapping layer 66 and an upper oxide layer 68. The high voltage gateinsulation layer 74 h may cover the second active region 60 on bothsides of the high voltage gate electrode 78 h. Similarly, the lowvoltage gate insulation layer 74 l may cover the third active region 62on both sides of the low voltage gate electrode 78 l. This occursbecause the insulation layers disposed under the high voltage gateelectrode 78 h and the low voltage gate electrode 78 l are not removedduring the etch process due to the etch selectivity of polysilicon andsilicon oxide. The residual insulation layer may be removed in anover-etch process or in a cleaning process or it may be left in place.

An interlayer insulation layer may be formed on the substrate with thegate lines 78 w, the high voltage gate electrode 78 h and the lowvoltage gate electrode 78 l. A line-shaped conductive pattern thatcorresponds to a common source line and a plurality of plug-typeconductive patterns that correspond to a bit line plug are formed in theinterlayer insulation layer parallel to the word lines 78 w. Electrodeswhich are electrically connected to the second active region 60 and thethird active region 62 may be formed simultaneously.

FIGS. 21 through 26 are cross-sectional views showing a non-volatilememory devices and methods of fabricating the same in accordance withsecond embodiments of the present invention. As shown in FIG. 21, a padinsulation layer 53 is formed on the substrate 50 in both the cellregion “b” and in the low voltage region “d”. A first oxide layer 52 isalso formed on the substrate 50 in the a high voltage region “c”. Thepad insulation layer 53 and the first oxide layer 52 may be formed inthe manner discussed above with respect to the embodiment depicted inFIGS. 13 and 14. A hard mask layer 55 may then be formed on the entiresurface of the substrate 50.

As shown in FIG. 22, a plurality of device isolation layers 56 areformed on the semiconductor substrate 50. The device isolation layer 56may be formed using trench isolation technology and/or by the methodsdiscussed above with respect to the first set of embodiments of thepresent invention. The device isolation layers 56 define a plurality offirst active regions 58 in the cell region “b”, a second active region60 in the high voltage region “c” and a third active region 62 in thelow voltage region “c”. The hard mask layer 55 is then removed and thepad insulation layer 53 is removed from both the cell region “b” and thelow voltage region “d”.

A lower oxide layer 64 and a charge-trapping layer 66 are formed overthe entire surface of the substrate. As illustrated in FIG. 23, thecharge trapping layer 66 may then be removed from the high voltageregion “c”, from the low voltage region “d” and the selection gateregion SR of the cell region “b”.

As shown in FIG. 24, a second oxide layer 76 may then be formed on theentire surface of the substrate. This second oxide layer 76 may then beremoved from the cell region “b”. The second oxide layer 76 maycomprise, for example, a silicon oxide, a silicon oxynitride or aninsulation metal oxide layer. The charge trapping layer 66 may be formedof silicon oxynitride. Such an embodiment allows the second oxide layer76 of the cell region “b” to be removed using the charge trapping layer66 as an etch stop layer. In another approach, the second oxide layer 76may be formed using a thermal oxidation process. In this case, thesecond oxide layer 76 is not formed on the charge trapping layer 66 andtherefore the step of removing the second oxide layer 76 is notrequired.

As illustrated in FIG. 25, next an upper oxide layer 68 may be formed onthe entire surface of the substrate. The upper oxide layer 68 is thenremoved from the high voltage region “c” and the low voltage region “d”.The upper oxide layer 68 may be formed of an insulation metal oxide suchas, for example, aluminum oxide. Generally, an aluminum oxide layer isknown to have etch selectivity with respect to a silicon oxide layer. Asa result, the second oxide layer 76 that is disposed under the upperoxide layer 68 is not etched when the upper insulation layer 68 in thehigh voltage region “c” and the low voltage region “d” are removed viaan etch process. As is also seen in FIG. 25, these processing stepsleave a lower oxide layer 64, a charge trapping layer 66 and an upperoxide layer 68 stacked in the word line region WR of the cell region “b”while a lower oxide layer 64, a second oxide layer 76 and an upper oxidelayer 68 are stacked on the selection gate region SR of the cell region“b”. In the high voltage region “c” a first oxide layer 52, a loweroxide layer 64 and a second oxide layer 76 are stacked on the substrate50 and in the low voltage region “d” a lower oxide layer 64 and a secondoxide layer 76 are stacked on the substrate 50.

As is also shown in FIG. 25, a double layer conductive layer thatcomprises a polysilicon layer 70 and a low resistance layer 72 is formedover the entire surface of substrate. The low resistance layer 72 may beformed, for example, of tungsten, tungsten silicone, titanium silicideor cobalt silicide.

As shown in FIG. 26, the low resistance layer 72 and the polysiliconlayer 70 may then be successively patterned to form word lines 78 w inthe word line region WR, a selection gate line 78 s in the selectiongate region SR, a high voltage gate electrode 78 h in the high voltageregion “c” and a low voltage gate electrode 78 l in the low voltageregion “d”. As shown in FIG. 26, both the word lines 78 w and theselection gate line 78 s cross over the device isolation layers 56. Thehigh voltage gate electrode 78 h crosses over the second active region60 and the low voltage gate electrode 78 l crosses over the third activeregion 62. A charge storage insulation layer 74 c that comprises a loweroxide layer 64, a charge trapping layer 66 and an upper oxide layer 68is interposed between the gate lines 78 w and the first active regions58. This charge storage insulation layer may cover the entire topsurface of the word line region WR. A high voltage gate insulation layer74 h is interposed between the high voltage gate electrode 78 h and thesecond active region 60. This high voltage gate insulation layer 74 hmay comprise a stacked semiconductor structure that includes a patternedfirst oxide layer 52 a, a patterned lower oxide layer 64 a and apatterned second oxide layer 76 a. A low voltage gate insulation layer74 l is similarly interposed between the low voltage gate electrode 78 land the third active region 62. This low voltage gate insulation layer74 l may comprise stacked semiconductor structure that includes apatterned lower insulation layer 64 a and a patterned second oxide layer76 a.

FIGS. 27 through 32 are cross-sectional views showing non-volatilememory devices and methods of fabricating the same in accordance withthird embodiments of the present invention. As shown in FIG. 27, a firstpad insulation layer 53 is formed on the word line region WR of the cellregion “b”. This first pad insulation layer 53 comprises a pad oxidelayer 53 a and a pad nitride layer 53 b that are sequentially stacked.The pad oxide layer 53 a is also formed on the low voltage region “d”and on the selection gate region SR of the cell region “b”. A firstoxide layer 52 is formed on the high voltage region “c”.

As shown in FIG. 28, device isolation layers 56 are next formed on asubstrate to define a plurality of first active regions 58 in the cellregion “b”, a second active region 60 in the high voltage region “c”,and a third active region 62 in the low voltage region “d”. Then, thepad oxide layer 53 a is removed from the low voltage region “d” and theselection gate region SR of the cell region “b”. A portion of the firstoxide layer 52 is etched to reduce the thickness of the first oxidelayer 52. The pad oxide layer 53 a in the word line region WR is notetched during the etch of the first oxide layer 52 because it isprotected by the pad nitride layer 53 b.

As shown in FIG. 29, a second oxide layer 86 may then be formed on theentire surface of the substrate 50. This second oxide layer 86 may thenbe removed from the word line WR portion of the cell region “b”. Thesecond oxide layer 86 may also be formed using a thermal oxidationprocess. When a thermal oxidation process is used, the second oxidelayer 86 is not formed on the pad nitride layer 53 b and the step ofremoving the second oxide layer 86 from the word line region WR is notrequired.

Next, a lower oxide layer 64, a charge trapping layer 66 and an upperoxide layer 68 are formed on an entire surface of the substrate 50. Asshown in FIG. 30, the upper oxide layer 68 and the charge trapping layer66 may be removed from the selection gate region SR of cell region “b”,the high voltage region “c” and the low voltage region “d”.

As shown in FIG. 31, thereafter a conductive layer may be formed on theentire surface of the substrate. This conductive layer may comprise astacked low resistance layer 72 that is stacked on a polysilicon layer70. The low resistance layer 72 may comprise, for example, a tungsten,tungsten silicide, titanium silicide or cobalt silicide layer.

As shown in FIG. 32, the low resistance layer 72 and the polysiliconlayer 70 are sequentially patterned to form (a) word lines 78 w in theword line region WR, (b) a selection gate line 78 s in the selectiongate region SR, (c) a high voltage gate electrode 78 h in the highvoltage region “c” and (d) a low voltage gate electrode 78 l in the lowvoltage region “d”. Both the word lines 78 w and the selection gate line78 s cross over the device isolation layers 56. The high voltage gateelectrode 78 h crosses over the second active region 60, and the lowvoltage gate electrode 78 l crosses over the third active region 62. Acharge storage insulator 74 c, which comprises a lower oxide layer 64, acharge tapping layer 66 and an upper oxide layer 68, is interposedbetween the word lines 78 w and the first active regions 58. The chargestorage insulator 74 c may cover the entire top surface of the word lineregion WR. A second oxide layer 86 and the upper oxide layer 64 areinterposed between the selection gate line 78 s and the first activeregions 58 in the selection gate region SR. A high voltage gateinsulation layer 74 h is likewise interposed between the high voltagegate electrode 78 h and the second active region 60. The high voltagegate insulation layer 74 h may comprise a patterned first oxide layer 52a, a patterned second oxide layer 86 a and a patterned lower oxide layer64 a. A low voltage gate insulation layer 74 l is also interposedbetween the low voltage gate electrode 78 l and the third active region62. The low voltage gate electrode 78 l may comprise a patterned secondoxide layer 86 a and a patterned lower oxide layer 64 a.

FIGS. 33 through 36 are cross-sectional views showing non-volatilememory devices and methods of fabricating the same in accordance withfourth embodiments of the present invention. In these embodiments, thefabrication steps discussed above with respect to FIGS. 27 through 29are carried out to fabricate the structure depicted in FIG. 29. Then, asshown in FIG. 33, a first conductive layer 88 is formed on the secondoxide layer 86 and the first pad insulation layer 53. This firstconductive layer 88 may be formed of polysilicon.

As shown in FIG. 34, the first conductive layer 88 and the padinsulation layer 53 are then removed from the word line region WR of thecell region “b” to expose the first active regions 58. Then, a loweroxide layer 64, a charge trapping layer 66 and an upper oxide layer 68are sequentially formed on the entire surface of the substrate 50. Next,a second conductive layer 90 is formed on the upper oxide layer 68. Thesecond conductive layer 90 may also be formed of polysilicon.

As shown in FIG. 35, the second conductive layer 90, the upper oxidelayer 68, the charge trapping layer 66 and the lower oxide layer 64 arenext removed from the selection gate region SR, the high voltage region“c” and the low voltage region “d”. As a result, the word line WP iscovered with second conductive layer 90, and the selection gate regionSR, the high voltage region “c” and the low voltage region “d” arecovered with the first conductive layer 88. A low resistance layer 92 isthen formed on the entire surface of the substrate 50. The lowresistance layer 92 may be, for example, a tungsten, tungsten silicide,titanium silicide or cobalt silicide layer. A polysilicon layer may befurther formed on the entire surface of substrate.

Referring next to FIG. 36, the low resistance layer 92 and the secondconductive layer 90 are sequentially patterned in the word line regionWR to form a plurality or parallel word lines 78 w. The low resistancelayer 92 and the first conductive layer 88 are patterned at theselection gate region SR to form selection gate lines 78 s parallel tothe word lines 78 w. The low resistance layer 92 and the firstconductive layer 88 are also patterned to form a high voltage gateelectrode 78 h in the high voltage region “c” and to form a low voltagegate electrode 78 l in the low voltage region “d”. As shown in FIG. 36,a high voltage gate insulation layer 74 h that may comprise a patternedfirst oxide layer 52 a and a second oxide layer 86 a is interposedbetween the high voltage gate electrode 78 h and the second activeregion 60. A low voltage gate insulation layer 74 l that is formed of apatterned second oxide layer is likewise interposed between the lowvoltage gate electrode 78 h and the third active region 62.

FIGS. 37 through 41 are cross-sectional views showing non-volatilememory devices and methods of fabricating the same in accordance withfifth embodiments of the present invention. As shown in FIG. 37, a padinsulation layer 53 comprising a pad oxide layer 53 a and a pad nitridelayer 53 b are formed on the substrate in the word line region WR of thecell region “b”. A first oxide layer 52 is formed on the substrate inthe high voltage region “c” and a second oxide layer 54 is formed on thesubstrate in the selection gate region SR of cell region “b” and in thelow voltage region “d”. Then, a first conductive layer 94 and a hardmask layer 95 are formed. The first conductive layer 94 may be formed ofpolysilicon and the hard mask layer 95 may be formed of silicon nitride.

As shown in FIG. 38, trench device isolation layers 56 are formed in thesubstrate 50 and then the hard mask layer 95 is removed. The deviceisolation layers 56 may be formed using self-aligned shallow trenchisolation technology. The device isolation layers 56 define a pluralityof first active regions 58 in the cell region “b”, a second activeregion 60 in the high voltage region “c”, and a third active region 62in the low voltage region “d”. A first conductive pattern 94 a is formedon the active regions 58, 60 and 62. The first conductive pattern 94 ais disposed between the device isolation layers 56 such that thesidewalls of each portion of the first conductive pattern 94 a are incontact with the sidewalls of the adjacent device isolation layers 56.

Next, as shown in FIG. 39, the first conductive pattern 94 a and the padinsulation layer 53 are removed from the word line region WR. A loweroxide layer 64, a charge trapping layer 66 and an upper oxide layer 68are sequentially formed on the entire surface of the substrate. A secondconductive layer 96 is formed on the upper oxide layer 68. The secondconductive layer 96 may be formed of polysilicon.

As shown in FIG. 40, the second conductive layer 96, the upper oxidelayer 68, the charge trapping layer 66 and the lower oxide layer 64 areremoved in the selection gate region SR, the high voltage region “c” andthe low voltage region “d”, thereby exposing the first conductivepattern 94 a and the device isolation layers 56. A third conductivelayer 98 and a low resistance layer 100 are formed on the entire surfaceof the substrate. The third conductive layer 98 may be formed ofpolysilicon and the low resistance layer 100 may be formed of tungsten,tungsten silicide, titanium silicide or cobalt silicide.

As shown in FIG. 41, the low resistance layer 100, the third conductivelayer 98 and the second conductive layer 96 are patterned to form aplurality of parallel word lines in the word line region WR. The lowresistance layer 100, the third conductive layer 98 and the conductivepattern 94 a are patterned at the selection gate region SR to fromselection gate lines in parallel to the word lines. The low resistancelayer 100, the third conductive layer 98 and the first conductivepatterns 94 a are patterned in the high voltage region “c” and the lowvoltage region “d” to form a high voltage gate electrode 78 h and a lowvoltage gate electrode 78 l, respectively. In the embodiments depictedin FIG. 41, the gate lines 78 w may be comprised of the secondconductive pattern 96 a, the third conductive pattern 98 a, and the lowresistance patterned layer 100 a. The high voltage gate electrode 78 hand the low voltage gate electrode 78 l are triple layer structurescomprising the first conductive pattern 94 b, the third conductivepattern 98 a and the low resistance patterned layer 100 a. A highvoltage gate insulation layer 74 h that comprises a first oxide layer isinterposed between the high voltage gate electrode 78 h and the secondactive region 60. Likewise, a low voltage gate insulation layer 74 lthat comprises a second oxide layer is interposed between the lowvoltage gate electrode 78 l and the third active region 62.

In the above-described embodiments of the present invention, the loweroxide layer 64 may be formed of, for example, silicon oxide, siliconoxynitride or metal oxide. The charge trapping layer 66 may be formed ofsilicon nitride or silicon oxynitride. The charge trapping layer 66 maybe formed of material having etch selectivity with respect to the loweroxide layer. The upper oxide layer 68 may, for example, be formed ofsilicon oxide, silicon oxynitride or an insulate metal oxide such asaluminum oxide. In non-volatile memory devices according to embodimentsof the present invention, the charge storage insulator 74 c may coverthe cell region or, alternately, may be disposed only under the gatelines. Likewise, the high voltage gate insulation layer 74 h and the lowvoltage gate insulation layer 74 l may be formed only under the gateelectrode or also formed on the active region on both sides of the gateelectrode.

FIG. 42A is a cross-sectional diagram, taken along the line B-B of FIG.6, illustrating a part of a wordline region WR of a non-volatile memorydevice according to certain embodiments of the present invention. Asillustrated in FIG. 42A, a charge storage insulation layer 224 may bedisposed to cover an entire surface of a substrate 220 where deviceisolation layers and active regions are formed. A plurality of wordlinesWn are disposed on the charge storage insulation layer 224 to cross overthe active regions and the device isolation layers. The charge storageinsulation layer 224 may include a lower insulation layer 214, a chargestorage layer 216, and an upper insulation layer 218. The upperinsulation layer 218 may include at least one metal oxide layer. Themetal oxide layer may include a metal listed in Group III or VB of thePeriodic Table. The metal oxide layer may also be doped with elementslisted in Group IV of the Periodic Table. Thus, for example, the metaloxide layer may be made of at least one selected from the groupconsisting of Al₂O₃, HfO₂, HfAlO, HfAlON, ZrO₂, ZrAlO, HfSiO, andHfSiON. The upper insulation layer may further include a protectiveinsulation layer sandwiched between the metal oxide layer and the gatelines (including the word lines, the ground select lines and the stringselect lines) in certain embodiments of the present invention.

The non-volatile memory devices according to embodiments of the presentinvention may also include spacer insulation layers on sidewalls of thewordlines Wn, the round select lines GSLn, and/or the string selectlines SSLn. FIG. 42B illustrates one such embodiment of the presentinvention in which spacer insulation layers are included on sidewalls ofthe wordlines Wn, the ground select lines GSLn, and the string selectlines SSLn.

As illustrated in FIG. 6, adjacent wordlines (e.g., W1 and W2) arespaced apart by a first distance. The wordlines that are adjacent to aground select line (e.g., W1 and GSL1) are also spaced by the firstdistance, as are the wordlines that are adjacent to a string select line(e.g. Wm and SSL2). Adjacent ground select lines (e.g., GSL2 and GSL1)are spaced by a second distance that is longer than the first distance.Adjacent string select lines (e.g., SSL1 and SSL2) are likewise spacedby the second distance.

As illustrated in FIG. 42B, between gate lines spaced by a firstdistance, (e.g., wordlines W1 and ground select line GSL1 and wordlineWn and string select line SSL1), first spacer insulation layers 230 care provided. As shown in FIG. 42B, the first spacer insulation layers230 c on facing sidewalls of adjacent gate lines connect with eachother. As is also shown in FIG. 42B, with respect to adjacent gate linesthat are spaced by the second distance (e.g., ground select lines GSL2and GSL1 and string select lines SSL1 and SSL2), second spacerinsulation layers 230 s are provided that are spaced apart from eachother and that do not connect like the first spacer insulation layers230 c.

As is also shown in FIG. 42B, the charge storage layer 224 is removed inthe area between the ground select lines GSLn-1 and GSLn and in the areabetween the string select lines SSLn-1 and SSLn. The portion of thecharge storage layer that is removed may be aligned with the edges ofthe second spacer insulation layer 230 s. Each removed portion of thecharge storage layer 224 may expose an active region. According to someembodiments of the present invention, even when other insulation layers(not shown in FIG. 42B) are included in the area between adjacent groundselect lines and/or in the area between adjacent string select lines,the edges of the charge storage layer 224 are aligned with respectivesidewalls of the spacer insulation layers 230 s to expose the activeregions, irrespective of the kinds and/or stacked configuration of theinsulation layers.

As is also illustrated in FIG. 42B, in certain embodiments of thepresent invention, an etch-stop layer 232 may be disposed conformally onan entire surface of the substrate 200. An interlayer dielectric 250 maythen be disposed uniformly on the etch-stop layer 232. A common sourceline CSL and a bitline contact BC are connected with respective activeregions through the interlayer dielectric 250 and the etch-stop layer232.

In a non-volatile memory device according to further embodiments of thepresent invention, the thickness of the charge storage insulation layer224 in the regions between the wordlines Wn may be smaller (i.e.,thinner) than the thickness of the charge storage insulation layer 224in the regions below the wordlines Wn. FIGS. 43A-47A and FIGS. 43B-47Bare cross-sectional diagrams of a wordline region, each being takenalong a line B-B of FIG. 6, of exemplary embodiments of the presentinvention that include such a configuration. In each case, the Fig. thatincludes the designation “A” (e.g., FIG. 43A) is a cross-sectionaldiagram of the device after the formation of the wordlines, whereas theFig. with the same number that is designated “B” (e.g., FIG. 43B) is across-sectional diagram of the device after additional layers have beenformed.

As illustrated in FIG. 43A, the non-volatile memory device according toone such embodiment of the present invention includes a charge storageinsulation layer 224 that comprises a lower insulation layer 214, acharge storage layer 216, and an upper insulation layer 218. The upperinsulation layer 218 has recessed regions between the wordlines that arealigned with the sidewalls of the respective wordlines Wn. As a result,the upper insulation layer 218 in the regions between adjacent wordlinesWn is thinner than the upper insulation layer 218 in the regions belowthe wordlines Wn. Alternatively, the upper insulation layer 218 in theregions between the wordlines Wn may be removed completely to expose thecharge storage layer 216.

As in the embodiments of FIG. 42B in the embodiment of FIG. 43 (see FIG.43B), the distance between each word line and any other adjacent gateline is a first distance, whereas the distance between adjacent selectlines is a second distance. First spacer insulation layers 230 c aredisposed on sidewalls of adjacent gate lines that are separated by thefirst distance such that the first spacer insulation layers 230 c onopposing gate lines connect with each other. Between gate lines spacedby the second distance, second spacer insulation layers 230 s areprovided which are spaced apart from each other. The portions of thecharge storage layer 224 between adjacent ground select lines andbetween adjacent string select lines are removed to expose activeregions. The portions removed are aligned with the sidewalls of thesecond spacer insulation layers 230 s. Even when other insulation layersare disposed between adjacent ground select lines and/or betweenadjacent string select lines, they are aligned with sidewalls of thespacer insulation layers 230 s to expose active regions, irrespective ofkinds and stacked configuration of the insulation layers.

FIGS. 44A and 44B depict another embodiment of the present invention. Asillustrated in FIG. 44A, in the regions between adjacent wordlines, aportion of the charge storage layer 216 as well as the upper insulationlayer 218 are removed. As a result, the charge storage insulation layer216 in the regions between adjacent wordlines Wn is thinner than thecharge storage insulation layer 216 in the regions below the wordlinesWn.

In the non-volatile memory devices according to embodiments of thepresent invention, the charge storage layer may, for example, be asilicon-rich oxide or an insulation layer including conductive dotsrather than an insulation layer. As is shown in FIG. 44B, spacerinsulation layers 230 c and 230 s may be disposed on sidewalls of thewordlines Wn, sidewalls of the ground select lines GSLn-1 and GSL, andsidewalls of the string select lines SSLn-1 and SSLn. As in theembodiment of FIGS. 43A and 43B described above, edges of the chargestorage layer 224 may be discontinuous, having edges that are alignedwith the spacer insulation layers 230 s in the regions between adjacentground select lines and in the regions between adjacent string selectlines to expose active regions.

FIGS. 45A and 45B depict an exemplary embodiment of the presentinvention in which the charge storage layer 216 comprises an insulationlayer that includes conductive dots. As shown in FIG. 45A, the chargestorage layer 216 includes a plurality of conductive dots 217. Theconductive dots 217 constitute a plurality of charge storage sites,which are electrically insulated from each other, in the insulationlayer. As shown in FIG. 45B, in this embodiment spacer insulation layers230 c and 230 s may be disposed on sidewalls of the wordlines Wn,sidewalls of the ground select lines GSLn-1 and GSLn, and sidewalls ofthe string, select lines SSLn-1 and SSLn, and the charge storage layer224 may be aligned with the spacer insulation layer 230 s between theground select lines and between string select lines to expose activeregions as in the embodiments described above with respect to FIGS. 43Aand 43B and FIGS. 44A and 44B.

As illustrated in FIG. 46A, according to still further embodiments ofthe present invention the charge storage layer 216 may includeconductive dots 217, and the upper insulation layer 218 may haverecessed regions that are aligned with the sidewalls of respective ofthe wordlines Wn. In such embodiments, the thickness t2 of the upperinsulation layer 218 in the regions between the wordlines Wn may besmaller than the thickness t1 of the upper insulation layer 218 in theregions below the wordlines Wn. In still other embodiments, the upperinsulation layer 218 may be removed completely in the regions betweenadjacent wordlines Wn to expose the charge storage insulation layer 224.Further, as illustrated in FIG. 47A, the upper insulation layer 218, aswell as a portion of the charge storage layer 216 (including conductivedots 217) may be removed in the regions between the wordlines Wn. Athickness t4 of the charge storage insulation layer 216 remaining in theregions between the wordlines may be smaller than a thickness t3 of thecharge storage insulation layer 216 in the regions below the wordlinesWn. Also, as shown in FIGS. 46B and 47B, in these modified embodiments,spacer insulation layers 230 c and 230 s may be disposed on sidewalls ofthe wordlines Wn, of the ground select lines and of the string selectlines, and the charge storage layer may be aligned with the spacerinsulation layers 230 s between the ground select lines and between thestring select lines to expose active regions.

FIGS. 48 through 50 are cross-sectional views illustrating methods offabricating non-volatile memory devices using an ion implantationprocess according to embodiments of the present invention. In thesefigures, “HV region” refers to the high voltage region of the device andis a cross-sectional view taken along the line E-E of FIG. 9 and “LVregion” refers to the low voltage region of the device and is across-sectional view taken along the line F-F of FIG. 11. The “cellregion” is a cross-sectional view taken along part of the line B-B ofFIG. 6. The cross-section of the cell region has been simplified forease of explanation.

As illustrated in FIG. 48, a non-volatile memory device according toembodiments of the present invention includes a cell region and aperipheral region. A plurality of device isolation layers (not shown inFIG. 48) are formed in a substrate 300 to define a plurality of firstactive regions in a cell region of the device, and a plurality of secondactive regions in a peripheral region of the device.

In the cell region, a charge storage insulation layer 315 is formed onat least the first active regions. The charge storage insulation layer315 may comprise a lower insulation layer 311, a charge storage layer312, and an upper insulation layer 313. A plurality of gate lines 320are formed on the charge storage insulation layer 315.

The peripheral region may comprise a high voltage region and a lowvoltage region. A first gate electrode 350 is formed in the high voltageregion, and a second gate electrode 360 is formed in the low voltageregion. A first gate insulation layer 355 may be interposed between thefirst gate electrode 350 and the substrate 300, and a second gateinsulation layer 365 may be interposed between the second gate electrode360 and the substrate 300. The first gate electrode 350 may be a highvoltage gate electrode, and the second gate electrode 360 may be a lowvoltage gate electrode.

An ion implantation mask 380 may be formed on the substrate 300 thatexposes the cell region and covers the peripheral region. Subsequently,a first ion implantation process is carried out in the cell regionwhereby source/drain regions 330 may be formed in the active regions ofthe cell region.

The first ion implantation process may comprise a non-tilt ionimplantation process and a tilt ion implantation process. Herein, a“non-tilt ion implantation process” refers to an ion implantationprocess wherein impurity ions are injected at an incident angle of aboutzero (0) degrees relative to a line that is orthogonal to the substrate.In the non-tilt ion implantation process, impurity ions such as P, As,BF₂, B, etc. may be injected with an energy of, for example, about 5˜100keV and a concentration of, for example, about 1E12˜1E15 ions/cm².

FIG. 49 illustrates a tilt ion implantation process according toembodiments of the present invention. In some embodiments of the presentinvention, the tilt ion implantation process is carried out after thenon-tilt ion implantation process. In other embodiments, the tilt ionimplantation process is carried out prior to the non-tilt ionimplantation process.

In the tilt ion implantation process, impurity ions are injected at anincident angle θ relative to a line that is orthogonal to the substrate.For example, where an interval between adjacent gate lines 320 is L1,and a height of the gate lines 320 from the charge storage insulationlayer 315 is L2, impurity ions may be injected at an incident angle ofabout θ where θ is defined as θ≦tan⁻¹ (L1/L2). Also, impurity ions maybe injected in one direction or two directions. Unless there is thecharge storage insulation layer 315 between the gate lines 320, a heightof the gate lines 320 from the substrate 300 may be L2.

In the tilt ion implantation process, impurity ions such as P, As, BF₂,B, etc. may be injected with an energy of for example, about 5˜100 keVand a concentration of for example, about 1E12˜1E15 ions/cm².

As illustrated in FIGS. 48 and 49, the first ion implantation processmay comprise both a non-tilt ion implantation process and a tilt ionimplantation process. In other embodiments of the present invention, thefirst ion implantation process may comprise only one of the non-tilt ionimplantation process and the tilt ion implantation process.

As illustrated in FIG. 50, a second ion implantation process is carriedout after removing the ion implantation mask covering the peripheralregion. Thereby, source/drain regions 370 are formed in the activeregions of the peripheral region.

In the second ion implantation process, impurity ions such as P, As,BF₂, B, etc. may be injected with an energy of, for example, about 5˜100keV and a concentration of, for example, about 1E12˜1E15 ions/cm². Inthe second ion implantation, impurity ions may be injected in both ofthe cell region and the peripheral region. According to embodiments ofthe present invention, as ion implantation processes are carried outmore than twice in the cell region, the degree of freedom insource/drain regions of the cell region may increase. Also, a ionimplantation mask covering the cell region may be omitted during thesecond ion implantation process. Thus, the ion implantation process maybe simplified.

According to embodiments of the present invention, a charge storageinsulator comprising a plurality of layers may be formed not only on theactive region of the device, but also on the entire surface of the cellregion. Alternatively, the charge storage insulator may cross over theactive region and the device isolation layers along the gate patterns.In addition, the charge storage insulator may be formed after formingthe device isolation layers so that stress applied to the charge storageinsulator can be remarkably reduced. Moreover, the most upper layer ofthe charge storage insulator may be formed of a metal oxide to reducedefects by using the metal oxide layer as an etch stop layer, whilecontact holes or grooves are formed by patterning the interlayerdielectric layer.

While this invention has been particularly shown and described withreference to preferred embodiments thereof, it will be understood bythose skilled in the art that various changes in form and details may bemade therein without departing from the spirit and scope of theinvention as defined by the appended claims and equivalents.

1. A method of fabricating a non-volatile memory device comprising:forming a plurality of device isolation layers in a cell region of asubstrate to define a plurality of active regions, each of the pluralityof device isolation layers having a top surface and opposed sidesurfaces, and the active regions being defined between the side surfacesof the device isolation layers; forming a charge storage insulator onthe plurality of active regions and the plurality of device isolationlayers, the charge storage insulator being formed to cover the topsurfaces of the device isolation layers; forming a plurality of gatelines on the charge storage insulator that cross over the plurality ofdevice isolation layers; and forming conductive patterns that penetratethe charge storage insulator between some of the plurality of gate linesto electrically connect with at least some of the plurality of activeregions.
 2. The method of claim 1, wherein the charge storage insulatoris formed over substantially the entire surface of the cell region. 3.The method of claim 1, wherein forming a plurality of device isolationlayers in the cell region comprises: forming a pad insulation layer anda hard mask layer on the substrate; patterning the hard mask layer, thepad insulation layer and the substrate to form a plurality of paralleltrenches in the substrate in the cell region; and forming an insulationlayer on the patterned hard mask layer, the patterned pad insulationlayer and the patterned substrate to fill the plurality of paralleltrenches.
 4. The method of claim 3, further comprising: exposing thehard mask layer by polishing the insulation layers so as to divide theinsulation layer into the plurality of device isolation layers.
 5. Themethod of claim 4, further comprising removing the hard mask layer andthe pad insulation layer after the plurality of device isolation layersare formed.
 6. The method of claim 1, wherein forming the charge storageinsulator comprises sequentially forming a lower oxide layer, a chargetrapping layer and an upper oxide layer.
 7. The method of claim 6,wherein the upper oxide layer is formed of insulative metal oxide layer.8. The method of claim 1, wherein the device isolation layers are formedsuch that the top surfaces of the plurality of device isolation layersare disposed farther above the substrate than the top surfaces of theplurality of active regions.
 9. The method of claim 1, furthercomprising forming a plurality of contact plugs that penetrate thecharge storage insulator to electrically connect to the substrate.
 10. Amethod of fabricating a non-volatile memory device comprising: forming aplurality of device isolation layers in a substrate to define aplurality of first active regions in a cell region of the device, asecond active region in a high voltage region of the device and a thirdactive region in a low voltage region of the device, each of theplurality of device isolation layers having a top surface and opposedside surfaces, and at least the first active regions being definedbetween the side surfaces of the device isolation layers in the cellregion; forming a charge storage insulator on at least the first activeregions and the device isolation layers in the cell region, the chargestorage insulator being formed to cover the top surfaces of the deviceisolation layers in the cell region; forming a plurality of gate lineson the charge storage insulator; forming a first gate electrode over thesecond active region; forming a second gate electrode over the thirdactive region; forming a first insulation layer on the second activeregion prior to forming the first gate electrode; and forming a secondinsulation layer on the third active region prior to forming the secondgate electrode; wherein forming the first insulation layer comprisesforming a first oxide layer on the second active region followed byforming a lower oxide layer on the first oxide layer; and whereinforming the second insulation layer comprises forming a second oxidelayer that is thinner than the first oxide layer on the third activeregion followed by forming the lower oxide layer on the second oxidelayer.
 11. The method of claim 10, further comprising: formingconductive patterns that penetrate the charge storage insulator betweensome of the plurality of gate lines to electrically connect with atleast some of the plurality of first active regions.
 12. The method ofclaim 11, wherein the charge storage insulator is formed oversubstantially the entire surface of the cell region.
 13. The method ofclaim 10, wherein forming a plurality of device isolation layerscomprises: forming a pad insulation layer and a hard mask layer on thesubstrate; patterning the hard mask layer, the pad insulation layer andthe substrate to form a plurality of trenches in the substrate; andforming the plurality of device isolation layers that fill in theplurality of trenches.
 14. The method of claim 13, wherein forming theplurality of device isolation layers comprises forming an insulationlayer over substantially the entire surface of at least the cell regionand then exposing the hard mask layer by polishing the insulation layerso as to divide the insulation layer into the plurality of deviceisolation layers.
 15. The method of claim 14, further comprisingremoving the hard mask layer and the pad insulation layer after theplurality of device isolation layers are formed.
 16. The method of claim10, wherein forming the charge storage insulator comprises sequentiallystacking a lower oxide layer, a charge trapping layer and an upper oxidelayer, and wherein the upper oxide layer is formed of insulative metaloxide layer.
 17. The method of claim 10, wherein the device isolationlayers are formed such that the top surfaces of the plurality of deviceisolation layers are disposed higher than the top surfaces of theplurality of first active regions.
 18. A method of fabricating anon-volatile memory device, the method comprising: forming a pluralityof device isolation layers in a substrate to define a plurality ofactive regions; forming a charge storage insulation layer on theplurality of active regions and the plurality of device isolation layersby sequentially forming a lower insulation layer, a charge storage layerand an upper insulation layer; and forming a plurality of spaced apartgate lines on the charge storage insulation layer, the plurality ofspaced apart gate lines defining a plurality of regions between the gatelines, wherein the lower insulation layer and the charge storage layercover the plurality of active regions and the plurality of deviceisolation layers in the plurality of regions between the gate lines. 19.The method of claim 18, wherein the charge storage layer is formed of aninsulation layer or a silicon-rich oxide or an insulation layer thatincludes conductive dots.
 20. The method of claim 18, wherein the upperinsulation layer is formed such that the thickness of the upperinsulation layer in the plurality of regions between the gate lines issmaller than the thickness of the upper insulation layer in a pluralityof regions below the gate lines.
 21. The method of claim 18, whereinforming the upper insulation layer includes forming at least one metaloxide layer.
 22. The method of claim 21, wherein the metal oxide layeris formed of a metal listed in Group III or VB of the Periodic Table.23. The method of claim 22, wherein forming the metal oxide layerincludes doping the metal oxide layer with at least one element listedin Group IV of the Periodic Table.
 24. The method of claim 23 whereinthe metal oxide layer is formed of Al₂O₃, HfO₂, HfAlO, HfAlON, ZrO₂,ZrAlO, HfSiO, and/or HfSiON.
 25. The method of claim 21, wherein formingthe upper insulation layer further comprises forming a protectiveinsulation layer on the at least one metal oxide layer prior to formingthe gate lines.
 26. A method of fabricating a non-volatile memorydevice, the method comprising: forming a plurality of device isolationlayers in a substrate to define a plurality of active regions, each ofthe plurality of device isolation layers having a top surface andopposed side surfaces, and the active regions being defined between theside surfaces of the device isolation layers; forming a charge storageinsulation layer on the plurality of active regions and the plurality ofdevice isolation layers, the charge storage insulation layer beingformed to cover the top surfaces of the device isolation layers; forminga plurality of spaced apart gate lines on the charge storage insulationlayer, the plurality of spaced apart gate lines defining a plurality ofregions between the gate lines, wherein a first subset of the regionsbetween the gate lines have a first width and a second subset of theregions between the gate lines have a second width that is greater thanthe first width; forming spacer insulation layers on sidewalls of thegate lines that extend into respective of the regions between the gatelines; forming a plurality of interconnection patterns that are providedin respective ones of the second subset of the regions between the gatelines that electrically connect to the substrate; wherein each spacerinsulation layer that extends into the first subset of the regionsbetween the gate lines connects with another of the spacer insulationlayers, while the spacer insulation layers that extend into the secondsubset of the regions between the gate lines are spaced apart from eachother.
 27. The method of claim 26, wherein the charge storage insulationlayer is formed of an insulation layer or an insulation layer includingsilicon-rich oxide or an insulation layer including conductive dots. 28.The method of claim 26, wherein forming the charge storage insulationlayer comprises sequentially forming a lower insulation layer, a chargestorage layer and an upper insulation layer.
 29. The method of claim 28,wherein the lower insulation layer and the charge storage layer coverthe active region and the device isolation layer in the first subset ofthe regions between the gate lines.
 30. The method of claim 28, whereinthe upper insulation layer is formed such that a plurality of firstportions of the upper insulation layer in the respective first subset ofthe regions between the gate lines are thinner than a plurality ofsecond portions of the upper insulation layer that are below respectiveof the gate lines.
 31. The method of claim 28, wherein forming the upperinsulation layer includes forming at least one metal oxide layer. 32.The method of claim 31, wherein the metal oxide layer is formed of ametal listed in Group III or VB of the Periodic Table.
 33. The method ofclaim 32, wherein forming the metal oxide layer includes doping themetal oxide layer with at least one element listed in Group IV of thePeriodic Table.
 34. The method of claim 33, wherein the metal oxidelayer is formed of Al₂O₃, HfO₂, HfAlO, HfAlON, ZrO₂, ZrAlO, HfSiO,and/or HfSiON.
 35. The method of claim 31, wherein forming the upperinsulation layer further comprises forming a protective insulation layeron the at least one metal oxide layer prior to forming the gate lines.36. The method of claim 26, further comprising patterning the chargestorage insulation layer prior to forming the plurality ofinterconnection patterns such that edges of the charge storageinsulation layer are aligned with respective of the spacer insulationlayers that extend into the second subset of regions between adjacent ofthe gate lines.
 37. A method of fabricating a non-volatile memorydevice, the method comprising: forming a plurality of device isolationlayers in a substrate to define a plurality of active regions, each ofthe plurality of device isolation layers having a top surface andopposed side surfaces, and the active regions being defined between theside surfaces of the device isolation layers; forming a charge storageinsulation layer on the plurality of active regions and the plurality ofdevice isolation layers, the charge storage insulation layer beingformed to cover the top surfaces of the device isolation layers; forminga plurality of spaced apart gate lines that include word lines, groundselect lines and string select lines on the charge storage insulationlayer; and forming sidewall spacers on sidewalls of the gate lines,wherein each sidewall spacer on one of the word lines connects with thesidewall spacer on the gate line adjacent thereto.
 38. The method ofclaim 37, wherein the sidewall spacers on facing sidewalls of adjacentground select lines are spaced apart from each other, and wherein thesidewall spacers on facing sidewalls of adjacent string select lines arespaced apart from each other.
 39. The method of claim 38, furthercomprising patterning the charge storage insulation layer such thatedges of the charge storage insulation are aligned with the edges of thesidewall spacers in the areas between the adjacent string select linesand between the adjacent ground select lines.
 40. The method of claim37, wherein the upper insulation layer is formed such that regions ofthe upper insulation layer below the spaced apart gate lines are thickerthan regions of the upper insulation layer between the spaced apart gatelines.
 41. The method of claim 37, wherein forming the charge storageinsulation layer comprises sequentially forming a lower insulationlayer, a charge storage layer and an upper insulation layer.
 42. Themethod of claim 41 wherein forming the plurality of spaced apart gatelines includes recessing the upper insulation layer in regions betweenthe gate lines to expose the charge storage layer.
 43. The method ofclaim 42, wherein forming the plurality of spaced apart gate linesincludes recessing the charge storage layer such that regions of thecharge storage layer between the gate lines are thinner than regions ofthe charge storage layer below the gate lines.
 44. The method of claim42, wherein the charge storage layer is formed of an insulation layerincluding conductive dots.
 45. A method of fabricating a non-volatilememory device comprising: forming a plurality of device isolation layersin a substrate to define a plurality of first active regions in a cellregion of the device, and a plurality of second active regions in aperipheral region of the device, each of the plurality of deviceisolation layers having a top surface and opposed side surfaces, and atleast the first active regions being defined between the side surfacesof the device isolation layers in the cell region; forming a chargestorage insulation layer on the first active regions, the charge storageinsulation layer being formed to cover the top surfaces of the deviceisolation layers in the cell region; forming a plurality of gate lineson the charge storage insulation layer; forming a plurality of gateelectrodes over the second active regions; carrying out a first ionimplantation process in the cell region; and carrying out a second ionimplantation process in the cell region and the peripheral region,wherein source/drain regions are formed in the cell region and theperipheral region by carrying out the first and second ion implantationprocesses.
 46. The method of claim 45, further comprising forming an ionimplantation mask on the substrate that exposes at least portions of thecell region and covers the peripheral region before carrying out thefirst ion implantation process; and removing the ion implantation maskafter carrying our the first ion implantation process and beforecarrying out the second ion implantation process.
 47. The method ofclaim 45, wherein the first ion implantation process comprises a tiltion implantation process.
 48. The method of claim 47, wherein the firstion implantation process further comprises a non-tilt ion implantationprocess.
 49. The method of claim 48, wherein the non-tilt ionimplantation process is carried out prior to the tilt ion implantationprocess.
 50. The method of claim 47, wherein the tilt ion implantationprocess is carried out prior to the non-tilt ion implantation process.51. The method of claim 47, wherein an interval between adjacent gatelines is L1; a height of the gate lines from the charge storageinsulation layer is L2; and impurity ions are injected at an incidentangle that is less than or about equal to tan⁻¹(L1/L2).